Re: [PATCH 4/4] btrfs: add tree-checker for RAID-stripe-tree

[Qu Wenruo]

On 2023/9/18 23:44, Johannes Thumshirn wrote:
> Add a tree checker for RAID stripe tree items.
>
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
> ---
>   fs/btrfs/tree-checker.c | 42 ++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 42 insertions(+)
>
> diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
> index 01bba79165e7..ea84ca2767e9 100644
> --- a/fs/btrfs/tree-checker.c
> +++ b/fs/btrfs/tree-checker.c
> @@ -30,6 +30,7 @@
>   #include "file-item.h"
>   #include "inode-item.h"
>   #include "dir-item.h"
> +#include "raid-stripe-tree.h"
>
>   /*
>    * Error message should follow the following format:
> @@ -1635,6 +1636,44 @@ static int check_inode_ref(struct extent_buffer *leaf,
>   	return 0;
>   }
>
> +static int check_raid_stripe_extent(struct extent_buffer *leaf,
> +				    struct btrfs_key *key, int slot)
> +{
> +	struct btrfs_stripe_extent *stripe_extent =
> +		btrfs_item_ptr(leaf, slot, struct btrfs_stripe_extent);
> +
> +	if (unlikely(!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize))) {
> +		generic_err(leaf, slot,
> +"invalid key objectid for raid stripe extent, have %llu expect aligned to %u",
> +			    key->objectid, leaf->fs_info->sectorsize);
> +		return -EUCLEAN;
> +	}
> +
> +	if (unlikely(!btrfs_fs_incompat(leaf->fs_info, RAID_STRIPE_TREE))) {
> +		generic_err(leaf, slot,
> +	"RAID_STRIPE_EXTENT present but RAID_STRIPE_TREE incompat bit unset");
> +		return -EUCLEAN;
> +	}
> +
> +	switch (btrfs_stripe_extent_encoding(leaf, stripe_extent)) {
> +	case BTRFS_STRIPE_RAID0:
> +	case BTRFS_STRIPE_RAID1:
> +	case BTRFS_STRIPE_DUP:
> +	case BTRFS_STRIPE_RAID10:
> +	case BTRFS_STRIPE_RAID5:
> +	case BTRFS_STRIPE_RAID6:
> +	case BTRFS_STRIPE_RAID1C3:
> +	case BTRFS_STRIPE_RAID1C4:
> +		break;
> +	default:
> +		generic_err(leaf, slot, "invalid raid stripe encoding %u",
> +			    btrfs_stripe_extent_encoding(leaf, stripe_extent));
> +		return -EUCLEAN;
> +	}

Another thing we can check is the item size, the item size should be
aligned to a single record, or we can get garbage reading the last record.

Thanks,
Qu
> +
> +	return 0;
> +}
> +
>   /*
>    * Common point to switch the item-specific validation.
>    */
> @@ -1689,6 +1728,9 @@ static enum btrfs_tree_block_status check_leaf_item(struct extent_buffer *leaf,
>   	case BTRFS_EXTENT_DATA_REF_KEY:
>   		ret = check_extent_data_ref(leaf, key, slot);
>   		break;
> +	case BTRFS_RAID_STRIPE_KEY:
> +		ret = check_raid_stripe_extent(leaf, key, slot);
> +		break;
>   	}
>
>   	if (ret)